Enviro-S.T.A.R. conducts on-site HEPA Systems Inspections / D.O.P. (dioctyplthalate oil) smoke challenge testing for vacuums and negative air machines. DOP testing is often required by contract and is recommended for projects where there may not be significant separation from the general public (such as school sites or hospitals). DOP testing verifies the integrity of the HEPA filter and body of the negative air unit or vacuum. We inspect, certify, and make minor repairs to all equipment. 

DOP testing is typically required by contract and is often done at the job site. We service the Greater Bay Area and can visit sites in all of Central and Northern California. All DOP testing is scheduled on a first-come first-served basis. Please contact us for testing rates.



(510) 568-5996


10962 Bigge Street

San Leandro, CA 94577